Open AccessBeating lensing cosmic variance with galaxy tomography
Author(s) -
Pen UeLi
Publication year - 2004
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2004.07746.x
Subject(s) - physics , weak gravitational lensing , dark matter , galaxy , astrophysics , cosmic cancer database , spectral density , photometric redshift , redshift , gravitational lens , cosmic variance , strong gravitational lensing , gravitational lensing formalism , matter power spectrum , astronomy , statistics , mathematics
We discuss the use of cross‐correlations between galaxies with distance information and projected weak lensing dark matter maps to obtain a fully three‐dimensional dark matter map and power spectrum. On large scales ( l ≲ 100) one expects the galaxies to be biased, but not stochastic. I show that this allows a simultaneous solution of the full three‐dimensional evolving galaxy bias and the dark matter power spectrum simultaneously. Within the photometric redshift information of the Canada–France–Hawaii (CFH) lensing legacy survey, this allows a threefold reduction of statistical error, while a cross‐correlation with the Canadian Large Adaptive Reflector (CLAR) or other deep spectroscopic surveys allows a tenfold improvement in dark matter power accuracy on linear scales. This makes lensing surveys more sensitive to the cosmic equation of state and the neutrino masses.